I have an issue on iphone 3gs and u could help dude. My headset volume is very low. I replaced the headset mini speaker but the problem still. Do you know if there is a specific transistor on witch i could replace to fix the problem?

I have an iphone 3g 16 GB. It has a camera prob. Whenever i tap on camera icon to open it, it shows shutter n then light dims of display. N phone goes to switch mode with having that dim screen of shutter n no action more than this. I changed the camera but prob is same. Plz suggest the best